This invention relates to thiazolidines. More particularly, this invention relates to 2-(substituted imino)-N-(3-substituted phenyl)-3-thiazolidinecarbothioamides which are useful as insecticides.
Compounds containing the thiazolidine nucleus are not new; see, e.g., G. W. Stacy et al., J. Org. Chem., 23, 1760 (1958). 2-Iminothiazolidines also are known, most often in conjunction with an N-substituted thiocarbamoyl group; see, e.g., D. L. Klayman et al., Tetrahedron Lett., 1967, 281; D. L. Klayman et al., J. Heterocycl. Chem., 5, 517 (1968); Y. Yamamoto et al., Kyoritsu Yakka Daigaku Kenkyu Nempo, 1973, 46 and 53 [Chem. Abstr., 81, 136039z (1974)]; and D. L. Klayman et al., J. Org. Chem., 40, 2000 (1975).
It should be noted that in the preparation of 2-iminothiazolidines having a thiocarbamoyl substituent, the reaction usually employed can give either of two products, a 2-imino-3-thiocarbamoylthiazolidine or an N-(2-thiazolin-2-yl)thiourea, and the identity of the product has been in dispute. Thus, E. Cherbuliez et al., Helv. Chim. Acta, 49, 807 (1966), reported that the reaction of an aminoalkyl sulfuric monoester with an excess (or two equivalents) of an isothiocyanate in the presence of two equivalents of base usually gives a thiazoline, although N-methylcolamine sulfuric monoester reacts with one equivalent of phenyl isothiocyanate and two equivalents of base to give 2-phenylimino-3-methylthiazolidine. According to J. Rabinowitz, Helv. Chim. Acta, 52, 255 (1969), in those cases where the cyclization of .beta.-(N-thiocarbamoylamino)ethyl(or propyl) alcohols (or their orthophosphoric or sulfuric monoesters) gives 5-membered rings, the C.dbd.N double bond is always endocyclic.
On the other hand, Y. Yamamoto et al., Chem. Pharm. Bull. (Tokyo), 23, 2134 (1975), reported that the reaction of 2-alkylamino-2-thiazolines with an isothiocyanate gave the 3-N-alkylthiocarbamoyl-2-alkyliminothiazolidines, and not the 2-thiazolin-2-ylthioureas reported by Cherbuliez et al., supra.
3-N-Alkylthiocarbamoyl-2-iminothiazolidines are reported to possess anti-inflammatory activity. According to Netherlands Patent Specification No. 7417059, 3-alkyl-2-thiocarbamoylimino-3-thiazolines are active as insecticides, acaricides, and ovicides.